I've been at the garage for almost a year now. Had about 5 or 6 cars in with shagged turbos over that time. Add another 5 or 6 that had noisy turbos.
Is that a lot? Not really compared to the amount of cars we get in imo.
And were the shagged turbos down to poor maintenance? Dunno.
Not keeping on top of oil changes is the primary cause, or indeed, thrashing the balls out of it when cold (oil not doing what it should be doing when at working temp).
Over boosting is the second - Splits or poor joints between the blower and the manifold will make the turbo work harder.
(If Intercooled) Poor intercooler will not allow proper cooling, EGT will be sky-high causing issues with many components.
Turbocharged engines DO need more regular maintenance...... And that's why I'd never buy one of these piss poor ecoBoost things. They drive badly and are generally shit. Clearly, I'm not alone. I'd too rather have a 1.8 N/A Astra than a 1.4T.
My personal opinion, of course.
Last small engined FI car I drove was in Fuerteventura. A 1.2 Golf TSI. Not bad at all, until you get up into the hills. 1st gear is a must on every sharp corner, whereas, a larger engined NA car would have pulled in 2nd without a problem. Useless.